Prepare XMRig-HAC fork for public release

- Add DragonX coin and rx/hush algorithm support
- Update branding to XMRig-HAC / dragonx.is
- Update repository URLs to git.hush.is
- Replace example wallet addresses with placeholders
- Update .gitignore for build directories
- Document fork changes in README and CHANGELOG

src/base/net/stratum/Job.cpp

@@ -94,7 +94,14 @@ bool xmrig::Job::setBlob(const char *blob)
 
 bool xmrig::Job::setSeedHash(const char *hash)
 {
-    if (!hash || (strlen(hash) != kMaxSeedSize * 2)) {
+    if (!hash) {
+        return false;
+    }
+
+    const size_t len = strlen(hash);
+    // Accept any even-length hex string up to kMaxSeedSize*2 chars.
+    // RX_HUSH genesis key is 23 bytes (46 hex chars), not always 32.
+    if (len == 0 || len > kMaxSeedSize * 2 || (len % 2) != 0) {
         return false;
     }
 
@@ -102,7 +109,7 @@ bool xmrig::Job::setSeedHash(const char *hash)
     m_rawSeedHash = hash;
 #   endif
 
-    m_seed = Cvt::fromHex(hash, kMaxSeedSize * 2);
+    m_seed = Cvt::fromHex(hash, len);
 
     return !m_seed.empty();
 }
@@ -169,6 +176,12 @@ size_t xmrig::Job::nonceOffset() const
         return 147;
     }
 
+    // HUSH/DragonX has 140-byte header with nonce at offset 108
+    // (version:4 + prevHash:32 + merkleRoot:32 + saplingRoot:32 + nTime:4 + nBits:4)
+    if (algorithm() == Algorithm::RX_HUSH) {
+        return 108;
+    }
+
     return 39;
 }